Promoting road safety in urban environments requires an understanding of the factors that create hazardous road conditions. Illegal parking can cause a wide range of safety concerns, from blocking driver sightlines at crosswalks to obstructing bike lanes causing cyclists to enter vehicle traffic. Some of the causes of illegal parking have been studied before but there appears to be a gap in the literature regarding the influence of different on-street parking occupancy levels on illegal parking activity.
The relationship between on-street parking location occupancy and illegal parking is examined in this paper using two data sources. First, on-street parking payment transaction data for locations managed by the Toronto Parking Authority is used to determine parking location occupancy. Second, parking infraction data from the City of Toronto is used to examine the prevalence of illegal parking activity.
The study starts with identifying the five streets of each road type (arterial, collector, and local) within downtown Toronto that have the most parking infractions. The locations are selected only from downtown Toronto to help control for external factors (e.g., built environment). Next, parking infractions that occurred adjacent to paid on-street parking and that have potential safety implications are selected for further analysis. The parking infractions are then paired with the occupancy percentage of the adjacent paid on-street parking location at the time the infraction occurred. Finally, frequency distribution graphs are produced comparing the number of parking infractions to the adjacent parking location occupancy percentages. Some modifications are made to the frequency distribution graphs to control for certain factors (e.g., length of road). Linear and exponential regression models are produced to determine the trends within the frequency distribution graphs.
Overall, there is a positive relationship between parking location occupancy and illegal parking activity that may cause road safety concerns. For different times of the week, weekday mornings, afternoons, and evenings are analyzed but no weekend times were examined due to minimal data. All three times periods showed statistically significant relationships and parking location occupancy had a stronger effect on illegal parking activity in the morning. For the three types of road classification examined within the study (arterial, collector, and local), only local roads showed a statistically significant relationship. Finally, loading areas are shown to lower illegal parking activity.
The results show that there is a positive effect on road safety as on-street parking location occupancy decreases. This emphasizes the need for illegal parking to be managed through stringent enforcement and the creation of loading areas.